I've purchased shellac (pre-made but all natural ingredients), denatured alchohol, and 1 oz propolis chunks. I want to put a thin coat of a propolis-shellac mix on the inside of the hive, but cannot find how much alcohol to use for melting the propolis or what the ratio of that mixture to the shellac should be. I've search for this several times on the forum and in the Barefoot Beekeeping book, and find lots of mention, but no exact formulas. My plan is to dissolve the propolis in the denatured alcohol, and mix that with the shellac. Does that sound about right?

According to the technical data bulletin, the manufacturers recommend thinning in the following proportions:
-- I'm not sure what the "lbs to lbs" actually means -- can I interpret this as a straightforward ratio of parts?

It matters very little what dilution you use. If you make it very runny, you just end up using more alcohol that necessary and having to apply many coats to make a seal. It is a reversible 'reaction' - a physical change, rather than a chemical change - so you can remove shellac if necessary with alcohol at any time.

I add 250 grams of shallac flakes to 500 ml of alcohol, give it a good stir, let is 'soak' overnight, then stir in about another 500 ml, which seems about right to me.

Don't worry about it - just apply evenly and let the alcohol evaporate.

Phil is right that the lb cut isn't important.
But if you want to know what the lbs to lbs means it is a reference to how much shellac is dissolved in a gallon (not sure whose gallon originally). A 1 lb cut was made by dissolving 1 pound of shellac in a gallon of alcohol. So the 3 lb to 2 lb is how you would dilute a solution that started as 3 pounds of shellac dissolve in one gallon of alcohol to a solution that is the equivalent concentration of 2 pounds of shellac dissolved in one gallon of alcohol.
Generally speaking (in the U.S.), premixed shellac is a 3 lb cut. This is thick enough it can be difficult to get a nice, pretty finish on woodwork so is frequently diluted.

Thanks for posting that copy, Phil. I downloaded the version from Cornell and sent it to my Kindle, and for some reason, the pdf has dropped letters all over the place. Not sure if it is the Kindle or something bizarre my computer did!

A 1 lb cut was made by dissolving 1 pound of shellac in a gallon of alcohol. So the 3 lb to 2 lb is how you would dilute a solution that started as 3 pounds of shellac dissolve in one gallon of alcohol to a solution that is the equivalent concentration of 2 pounds of shellac dissolved in one gallon of alcohol. ????

I must admit that I mostly don't measure quantities, but simply stir in the shellac until it reaches a consistency that is similar to thin paint. It really doesn't matter, as the alcohol evaporates quickly and disappears.

Probably best applied in a well-ventilated room, or outdoors. And well away from naked flames...

Following up on this thread -- what type of shellac flakes are you purchasing, waxed (hydraulically filtered; aka "buttonlac") or dewaxed (dissolved in alcohol, then filtered/dried/pressed into sheets)?

Thanks,
- Barb

[quote="biobee"]It matters very little what dilution you use. If you make it very runny, you just end up using more alcohol that necessary and having to apply many coats to make a seal. It is a reversible 'reaction' - a physical change, rather than a chemical change - so you can remove shellac if necessary with alcohol at any time.

I add 250 grams of shallac flakes to 500 ml of alcohol, give it a good stir, let is 'soak' overnight, then stir in about another 500 ml, which seems about right to me.

Don't worry about it - just apply evenly and let the alcohol evaporate.[/quote]

Conserving wild bees

Research suggests that bumble bee boxes have a very low success rate in actually attracting bees into them. We find that if you create an environment where first of all you can attract mice inside, such as a pile of stones, a drystone wall, paving slabs with intentionally made cavities underneath, this will increase the success rate.

Most bumble bee species need a dry space about the size a football, with a narrow entrance tunnel approximately 2cm in diameter and 20 cm long. Most species nest underground along the base of a linear feature such as a hedge or wall. Sites need to be sheltered and out of direct sunlight.